1. Field of the Invention
The present invention relates to a cable-enrolling conductive thin-film sheet and a manufacturing method of the same. The sheet has a conductor layer sandwiched by a pair of insulating layers, and the conductor layer is connected to a core wire of an electrical cable.
2. Related Art
A motorcar is arranged with wiring harnesses for supplying an electrical power from a power source like a battery to electric equipment such as various types of lamps and motors and for transmitting control signals from a control unit to the electric equipment. Each wiring harness has a plurality of electrical cables.
Some of the electrical cables are shielded to prevent invasion of external electronic noises. The shield electrical cable has a shielding sheath having a knitted electrically conductive layer for preventing the invasion of the noises into the core wire.
Recently, a production cost reduction of a wiring harness has been desired. For the purpose, it has been proposed that a plurality of non-shielded electrical cables are made up into a bundle thereof and enrolled by a conductive thin film having a conductor layer to compose a wiring harness. This achieves a cost reduction of the wiring harness with prevention of noise invasion. Even in this configuration, the conductor layer needs to connect to a ground to remove the noises.
The aforementioned conductive thin-film sheet preferably has a pair of synthetic resin insulating layers each laminated on a front or rear face of the conductor layer. This eliminates pinholes generated due to corrosion of the conductor layer. The conductive thin-film sheet is partially stripped to connect the conductor layer to an end of a ground cable. Thereafter, the conductive thin film and the ground cable are secured to a support with bolts, nuts, washers, etc.
The stripping process of a portion of a sheath of the ground cable is required, thereby increasing a man hour in assembling thereof. The number of parts including bolts, nuts, and washers increases, resulted in an increased production cost of the conductive thin-film sheet. Moreover, the fastening of the bolts and nuts may cause a damage of the conductor layer not to establish a reliable electrical connection of the ground cable to the conductor layer. This is disadvantageous for removing external noises entering the core wire of the electrical cable.